Anton R. Roessler

Roessler then served the Confederacy as the chief draftsman at the Texas State Military Board's arsenal, also in Austin.

However, in February 1865, Roessler mysteriously arrived in Louisiana where he shared information to Union Army authorities concerning Confederate defenses, strategic resources, and geographic conditions in the eastern and central portions of Texas.

By April of that year, Roessler had helped the Engineer's Office of the Military Department of the Gulf create a map that aided in the Federal reoccupation and Reconstruction of Texas.

[11] Writing in 1887, future Texas state geologist Robert T. Hill commented on the qualifications of Shumard's survey members and noted that "Mr. Roessler, although a young man, possessed a good scientific education, [and] was a hard worker....".

[12] They noted the presence of timber, water, minerals, fossils, soil characteristics, and collected specimens and samples for further examination.

[13] Shumard reported that the mapmaking was difficult because the maps in the state's General Land Office in Austin were "more or less imperfect and the surveys in some instance exceedingly erroneous".

[15] Roessler later wrote that fellow geologist Samuel Botsford Buckley had made inappropriate accusations against himself and Shumard, who was thereby not reinstated by Texas Governor Sam Houston.

[16] At the beginning of the American Civil War, Roessler was still working as draftsman for the state's Geological and Agricultural Survey in Austin, Texas.

[1][6][9] By February 1865, however, Roessler was in Louisiana providing Union Army authorities with information about Texas' geography, strategic resources, road conditions, and Confederate defenses.

[6][17] He helped compile a map of Texas in New Orleans for the Engineer's Office of the Military Department of the Gulf that soon appeared in April of that year.

This map was reportedly used by General George Armstrong Custer and others during their occupation of Texas to implement Reconstruction policies following the war.

[15] During the late 1860s, Roessler worked as a geologist at the United States Land Office in Washington, D.C.[1][7][9] He returned to Austin during the administration of Republican governor Edmund J.

[24] According to the Royal Society Catalogue, he wrote six geological papers, but according to Samuel Wood Geiser, "his best work was in making maps of Texas".